Meningitis

MENINGITIS

Meningitis is an inflammatory process of the meninges and CSF

Demography of Meningococcal Meningitis

♦ Meningitis belt ♦ epidemic zones cases

♦ sporadic

Causes/Major Pathogens Type

Bacterial Viral infection

Pathogen (most Common) Strep pneumoniae, E-coli, Neisseria meningitis Coxsackie Virus, Echovirus, Enterovirus, Arbovirus, HIV, HSV-2

TB meningitis M. Tuberculosis Protozoal   Toxoplasma Gondii Infection Fung Fungal al infe infect ctio ion n (toxoplasmosis) Cryp Crypto toco cocc ccus us neof neofor orma mans ns (cryptococcal meningitis)

Other:

Progressive multifocal leukoencephalopathy (PML) Primary CNS lymphoma, HIVassociated dementia (HAD), Painful sensory and motor peripheral neuropathies, Neurosyphilis

PATHO PHYSIOLOGY  Microorganisms Direct to CSF

Via Blood Subarachnoid Immune Response Space from Astrocytes+Micro glia, Cytokin Release

Inc. BBB permeabilty Fluid leakage from vessels Vasogenic edema

Inc. no. of WBC in CSF Inflammation of  Meninges Interstitial edema (Inc. ECF)

Vasculitis of cerebral vessels Dec. cerebral blood flow Ischemia, cytotoxic edema

Cerebral Edema Dec. Cerebral blood flow, Ischemia, apoptosis (Brain Death) De ath)

MAJOR FORMS OF MENINGITIS Bacterial

Viral

More serious, less common Immunization available

Less serious, more common No immunization

for some

available

 Treatable with antibiotics

 Treatment includes waiting it out

More common in winter

More common in summer/ early fall

Classification • • • •

Acute pyogenic (bacterial) meningitis Acute aseptic (viral) meningitis Chronic bacterial infection (tuberculosis) (tu berculosis).. Acute focal suppurative infection (brain abscess, subdural and extradural empyema)

1) Acute Pyogenic Bacterial Meningitis

2) Acute Aseptic (Viral ) Meningitis • Can follow follow any viral infection • Less danger • Viral meningitis is usually self-limiting and treated • Fever delirium, lethargy, disorientation, symptomatically. malaise, headache most common • Stiff neck, photophobia, cranial nerve deficits less common • No focal neurological deficits • Gastrointestinal symptoms: diarrhea, colitis,

esophageal ulceration appear in 12-15% of 

3) Chronic bacterial infection (tuberculosis/  TB Meningitis)

Complications • Antibiotic treatment------ full recovery • Delayed or untreated cases--- can be fatal • Healing by fibrosis cause obliteration of 

subarachenoid space--- HYDROCEPHALUS • Brain abscess • Septic shock and skin rashes, why ?

1) Brain abscess • Causes :

1. complication of bacterial meningitis 2. bacterial endocarditis 3. pulmonary sepsis : pneumonia……etc 4. other sepsis Brain abscess cause a space occupying lesion in the brain

2) Skin rashes Is due to small skin bleed

• • All parts of the body are affected •  The rashes do not fade under pressure • Pathogenesis:

a. Septicemia b. wide spread endothelial damage c. activation of coagulation d. thrombosis and platelets aggregation e. reduction of platelets (consumption ) f. BLEEDING 1.skin rashes 2.adrenal hemorrhage Adrenal hemorrhage is called WaterhouseFriderichsen Syndrome. It cause acute adrenal insufficiency and is usually fatal

Work up for Meningitis Physical Exam • Brudzinski’s & Kernig’s sign • Nuchal rigidity • Papilledema Lumbar puncture to obtain CSF Chemistry (glucose & protein) Cytology (WBC# & %PMN’s) Gram stain or rapid identification test (< 24hrs) • CIE (Counterimmunoelectrophoresis) , coagglutination, or latex • •

•

agglutination Limulus lysate for gram negative endotoxin PCR (N.meningitidis, S. pneumoniae, H. influenzae, S. agalactiae, L. monocytogenes & enteroviruses) Lactate (>4.2 mmol/L considered positive for bacterial meningitis) Procalcitonin (> 5 micrograms/L suggestive of bacterial meningitis) C-reactive proteins (CRP) (Elevated in bacterial meningitis)

• • • Culture for pathogens (> 24hrs)

Blood, Urine, & Sputum Cultures

Kernig's sign The thigh is flexed on the abdomen, with the knee flexed; attempts to passively extend the knee elicit pain when meningeal irritation is present. Brudzinski's sign: passive flexion of the neck results in spontaneous flexion of  the hips and knees. Nuchal rigidity: Inability to flex the neck forward passively due to increased neck muscle tone. It occurs in 70% of  adult cases of bacterial meningitis

Jolt accentuation maneuver:

•The patient is told to rapidly rotate his or her head horizontally; if this does not make the headache worse, meningitis is unlikely. •It helps determine whether meningitis is present in patients reporting fever and headache. Kernig’s and Brudzinski’s signs have high specificity but low sensitivity(44%) for the diagnosis of meningitis. Jolt accentuation of  headache was determined to have a 97% sensitivity and 60% specificity. It has been suggested that absence of the jolt sign essentially excludes meningitis.

CSF Detail Report Changes in CSF Appearance WBC

< 5 mm3

Pyogenic  Tuberculosis (Bacterial)  Turbid/purule  Turbid/visco Clear/Turbid nt us 25-500 mm3 > 1000 mm3 < 500 mm3

< 5 mm3

10-100 mm3

Normal Crystal-clear

Viral

Mononuclear cells Polymorph cells Protein

Nil

Nil

0.2- 0.4 g/L

0.4-0.8 g/L

200-300/ mm3 0.5-2.0 g/L

Glucose

40-80 mg/dl

30-70 mg/dl

21

Duration of Antimicrobial Therapy for Bacterial Meningitis Based on Isolated Pathogen (A-III) a Duration in the neonate is 2 weeks beyond the first sterile CSF culture or >3 weeks, whichever is longer. •Tunkel AR, Hartman BJ, Kaplan SL, Kaufman BA, Roos KL, Scheld WM, Whitley RJ. Practice guidelines for  the management of bacterial meningitis. Clin Infect Dis 2004 Nov 1;39(9):1267-84. [120 references] PubMed

Adjunct Steroid Therapy for Infants, Children and Adults • Dexamethasone should be initiated 10-20 min prior  to, or at least concomitant with, the first antimicrobial dose, at 0.15 mg/kg every 6 h for 2-4 days.. days • Adjunctive dexamethasone should not be given to the patients who have already received antimicrobial therapy, because administration of  dexamethasone in this circumstance is unlikely to improve patient outcome At present, there are insufficient data to make a recommendation on the use of adjunctive dexamethasone in neonates with bacterial meningitis •Tunkel AR, Hartman BJ, Kaplan SL, Kaufman BA, Roos KL, Scheld WM, Whitley RJ. Practice guidelines for the management of 

2004

Management and Treatment Of TBM Daily administration of  Rifampicin 600 mg (450 mg for weight